phlegmatic /flɛɡˈmætɪk/adjective 2noun 1forms 3 adjective2 •Not easily excited to action or passion; calm; sluggish.Calm and phlegmatic, with a clear eye, Mr. Fogg seemed a perfect type of that English composure which Angelica Kauffmann has so skilfully represented on canvas. — 1873 •Generating, causing, or full of phlegm.cold and phlegmatic bodies — 1650 noun1 •One who has a phlegmatic disposition. formsphlegmatics · more phlegmatic · most phlegmatic